Final answer:
In a competitive market, if a firm produces a profit-maximizing level of output when the market price increases to $6, the resulting profit is $40. This is found by multiplying the output quantity (in this case 5) by the market price ($6) and subtracting the total costs.
Step-by-step explanation:
You're asking about the profit a firm would earn in a competitive market when the market price increases to $6 and the firm produces at a profit-maximizing level of output. According to the reference, once the market price increases to $6, the profit-maximizing level of output for the firm is quantity 5. At this level of output, the amount of profits made is $40.
To determine profits, we typically subtract the total cost from the total revenue. Since the market price is $6 and assuming the firm is producing output quantity 5, we multiply the output quantity by the market price to obtain total revenue. If the firm's total cost is less than this revenue at quantity 5, the difference would be the profit, which, in this example, is $40.